Antiknock motor fuel



Patented July 14, 1942 l Netherlands, assignor to Shell DevelopmentCompany, San Francisco, Calif., a corporation of Delaware No Drawing.Application May 9, 1939, Serial No. 272,628. In. the Netherlands May 20,1938 Claims.

This invention relates to gasoline-type motor fuels, i. e., motor fuelssuitable for use in gasoline engines, and more particularly deals withgasoline type motor fuels of high anti-knock properties containingmetaborganic knock suppressors.

As is well-known, certain mineral oil-soluble metal-organic compoundssuch as t'etraethyl lead, nickel and iron carbonyls, ethyl selenide,etc., have the property of suppressing detonation or knock in sparkignition engines. These compounds are generally known as anti-knockcompounds. While some of them are highly effective, they are all subjectto at least one or several serious disadvantages, such as insufiicientsolubility in hydrocarbons, low volatility, high toxicity, poor storagestability, corrosiveness to the engine, etc.

It is a purpose of this invention to provide a class of eflicient knocksuppressors comprising metal-organic compounds which are substantiallyfree from the above disadvantages or at least to possess them to a verymuch smaller extent. It is another purpose to provide non-toxicantiknock compounds readily soluble in gasoline having efficienciescomparable to those of tetraethyl lead.

I have discovered that members of a certain class of metal-organiccompounds are particularly effective as anti-knock agents because oftheir properties of an anti-knock value comparable with that of leadtetraethyl, low toxicity, good volatility and high solubility ingasoline. In particular, the solubility in gasoline of these compoundsis generally Very high, many members being miscible with gasoline in allproportions.

My anti-knock agents are compounds of a metal having an atomic number of26 to 29 inclusive, i. e. a metal selected from the class consisting ofiron, cobalt, nickel and copper and an organic substance containing theatom combinaation NCNCO or N-CNC-N, this combination containing at least2 double bonds each of which may be between two atoms of the chain, orbetween an atom of the chain, and a radical outside of the chain. Themetal is probably bound either to a nitrogen or an oxygen atom or both.

Particularly useful are metal compounds of substances with the followingbasic structure:

r r r HNVC=N VC=X in which X=O or NR4 and R1, 2, R3 and R4 representhydrogen atoms or organic radicals se lected from the group consistingof alkyl, aryl or 'strongly acidic, such as COOH, SO3H, e'tc.

groupings may partially occur in a ring system in which at least two ofthe atoms contained in the groupings participate as in the caseof 2 or 3amino-imidazoles, and acetylated alpha pyridines, while the N-CN- -C-Ngrouping may occur wholly in a ring system as is the case with 1,2,4triazoles. 1

As is well known in compounds of the above formula, the double bonds arecapable of shifting their exact location within the molecule dependingupon the surrounding conditions, thereby forming the enol and keto formsand amino or imino forms, respectively. Therefore the followingstructures are considered full equivalents of the above.

N=C-N=(IJXH The metal compounds of my invention may be conceived assalts or complex compounds or both. It is believed that the metal isusually attached to the oxygen, or to one of the nitrogen. atoms,

by replacement of a hydrogen atom as follows:

ing Patent 2,196,447. An example of a typical method of preparation isas follows:

About 15.5 parts by weight of pivalyl-allylimide chloride(CHs)sECCl=N-CHzOH=OHg which may be prepared by reacting pivalylchloride with allyl amine and treating the resulting pivalyl-allyl-amidewith phosphorus pentachloride to form pivalyl-allylamide chloride whichloses HCl spontaneously giving the desired pivalyl-allyl imide chloride,were dissolved in about 15 parts by weight of benzene. This solution wasadded slowly to a cooled solution consisting of about 8 parts by weightof butyramidine dissolved in about 12 parts by weight of henzene. Afterthe addition of the reactants was complete, the reaction was completedby heating the 'mixture to a temperature of about 80 C. for about onehour. The benzene was removed by evaporation. The residue was dissolvedin methyl ethyl ketone, and the product recovered in a purified form bycrystallization therefrom. Analysis of the product showed it to have thestruc- This novel compound may be designated as (allyl-pivalo)butyr-imidine hydrochloride.

The metal derivative of the compounds may be prepared by reacting themwith suitable compounds of the desired metal. Thus, for example, sodiumcompounds may be prepared by reaction with sodium ethylate. Thecorresponding copper cobalt iron or nickel compounds may be prepared byreacting suitable compounds of these metals with the sodium derivativesof the desired organic component, in an absolute alcohol solution.Further examples may be found in my co-pending application, Serial No.217,278, filed July 2, 1938.

If desired, gasoline type motor fuels may be prepared consistingentirely or predominantly of neutral oxyhydrocarbons, such as ethers,ketones, or alcohols, particularly those with branched carbon chains,and boiling within gasoline range, containing small amounts of ouranti-knock compounds. Such oxyhydrocarbons also may increase thesolubility in hydrocarbons of certain of my anti-knock compounds whichare relatively little soluble.

The amounts of my anti-knock compounds normally incorporated into thefuels to effect an improvement in the knock rating may vary from a baretrace to about .5% metal by weight of the fuel, although larger amountsmay be used, if desired. Moreover, my anti-knock compounds may be usedtogether with other known antiknock compounds such as tetraethyl lead.If necessary my anti-knock compounds may be stabilized by the additionof suitable stabilizing agents of which the aromatic amines areparticularly effective.

Of the four metals, iron, nickel, cobalt and copper found to possess thehigh anti-knock properties when combined with the organic compoundsdescribed, copper and cobalt are the most outstanding and effective.

Examples of types of suitable compounds are the copper, cobalt, nickeland iron the following: compounds of Containing the NC-NCN Containingthe N-O-N-O-O grouping grouping Imidines A t 1 L ted alnldines 2 or4-amino pyrimidines A gt a ylated a1 ha arm 1,2,4 triazoles Acetylatedis -ureas nopyndmes 2 or 3amino imidazoles Acetylated guanidines Thefollowing examples illustrate the manner in WhlCh these compounds may beused, and the highly satisfactory results obtained.

Example I As a result the octane number rose to 59.

Example II 0.1% by weight of copper in the form of the grip 13ccompolund of propionyl methyl acet- 1 me raise the octane number of from40 to 61.5. a gasolme Example III 0.1% by weight of copper in the formof the cuipric compound of alpha (pivalyl amino) pyr1 me.

raised the octane number of a gasoline from 40 Example IV 0.1% by weightof copper in the form of the cupric compound of butyryl isoamyl iso-ureaH2NC=NC=O (i) Can-1 05 11 iraizgd the octane number of a gasoline from39.

I claim as my invention:

1. improved motor fuel which comprises gasolme type motor fuel and asmall amount of a. knock suppressor comprising a compound combming ametal having an atomic number from 26 to 29 inclusive, with an organiccomponent. having a basic structure which contains an atom combinationselected from the group consisting of N=C-NC O and N=Cl\T-C=N or theirtautomers, the structure containing at least two double bonds.

2. An improved motor fuel which comprlses a gasolme type motor fuel anda small amount of a knock-suppressor comprising a compound of a metalhaving an atomic number from 26 to 29 inclusive, and an organiccomponent havin a structure represented by the formula 7 I R1 Ra Ra andits tautomers in which R1-R4 are radicals selected from the groupconsisting of hydrogen, alkyl, aryl and aralkyl radicals.

3. An improved motor fuel which comprises a gasoline type motor fuel anda small amount of a knock-suppressor comprising a compound of a metalhaving an atomic number from 26 to 29 inclusive, and an organiccomponent having a structure represented by the formula and itstautomers in which Ri-R3 are radicals selected from the group consistingof hydrogen, alkyl, aryl and aralkyl radicals.

4. The improved motor fuel of claim 1, the organic component of whichforms a ring in which at least two of the atoms of such structureparticipate.

5. The improved motor fuel of claim 1, which contains not more than .5%metal by weight of the motor fuel.

6. An improved motor fuel which comprises a gasoline type motor fuel anda small amount of the cupric compound of propionyl methyl acetamidine.

7. An improved motor fuel which comprises a gasoline type motor fuel anda small amount of the cupric compound of Mpivalyl amino) pyridine.

8. An improved motor fuel which comprises a gasoline type motor fuel anda small amount of a knock suppressor comprising a compound combining ametal having an atomic number from 26 to 29 inclusive, with an organiccomponent having a basic structure which contains an atom combination orits tautomeric equivalents, Where X is a radical selected from the groupconsisting of oxygen and imino radicals, and R1 to R3 are radicalsselected from the group consisting of hydrogen, alkyl, aryl and aralkylradicals.

9. An improved motor fuel which comprises a gasoline type motor fuel anda small amount of a knock suppressor in excess of its solubility in thefuel, comprising a compound combining a metal having an atomic numberfrom 26 to 29 inclusive, with an organic component having a basicstructure which contains an atom combination selected from the groupconsisting of N=C-N-C=O and N=CNC=N or their tautomers, the structurecontaining at least two double bonds, and a quantity of a mutual solventsoluble in the fuel boiling within the gasoline boiling range, selectedfrom the group consisting of alcohols, ketones, ethers and amines,sufficient completely to dissolve the knock suppressor.

10. An improved motor fuel which comprises a gasoline type motor fueland a small amount of a knock suppressor in excess of its solubility inthe fuel, comprising a compound combining a metal having an atomicnumber from 26 to 29 inclusive, with an organic component having a basicstructure which contains an atom combination selected from the groupconsisting of N=C-NC=O and N=C-NC=N or their tautomers, the structurecontaining at least two double bonds and stabilized by the addition ofsmall quantities of aromatic amines.

ADRIANUS JOHANNES VAN PESKI.

